Hibernate介绍:Hibernate是一种“对象-关系型数据映射组件”,它使用映射文件将对象(object)与关系型数据(Relational)相关联,在Hibernate中映射文件通常以".hbm.xml"作为后缀。
包:com.cn.beans
与数据库表t_user(id主键,name)对应的工程中POJO代码(Javabean):Tuser.Java
package com.cn.beans;
import java.io.Serializable; import javax.annotation.Generated; public class Tuser implements Serializable { /**
*
*/
private static final long serialVersionUID = 1L; private Integer id;
private String name;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
} }
POJO与数据库表对应的映射文件:Tuser.hbm.xml
<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping package="com.cn.beans">
<class name="com.cn.beans.Tuser" table="t_user">
<id name="id" column="id" type="int">
</id>
<property name="name" column="name" type="string">
</property>
</class>
</hibernate-mapping>
包:com.cn.hibernate.test:HibernateBaseTest.java代码:
package com.cn.hibernate.test; import java.util.List; import junit.framework.Assert;
import junit.framework.TestCase; import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration; import com.cn.beans.Tuser; public class HibernateBaseTest{
Session session=null; //初始化hibernate的Session
protected void setUp(){
try{
Configuration config=new Configuration().configure();
SessionFactory sessionFactory=config.buildSessionFactory();
session = sessionFactory.openSession();
System.out.println("连接数据库成功!");
}catch(HibernateException e){
e.printStackTrace();
System.out.println("连接数据库失败!");
}
} public static void main(String[] args) {
HibernateBaseTest j = new HibernateBaseTest();
j.setUp();
//j.testInsert();
j.testSelect();
}
//teardown()方法用于关闭用setUp打开的hibernate中的Session;
protected void teardown(){
try{
session.close();
System.out.println("关闭数据库");
}catch(HibernateException e){
e.printStackTrace();
}
} public void testInsert(){
Transaction tran=null;
try{
tran=session.beginTransaction();
Tuser user=new Tuser();
user.setId(8);
user.setName("Emma11");
session.save(user);
session.flush();
tran.commit();
session.close();
}catch(HibernateException e){
e.printStackTrace();
if(tran!=null){
try{
tran.rollback();
}catch(HibernateException e1){
e1.printStackTrace();
}
}
}
} //对象读取(select)测试,请保证运行之前数据库中已经存在name='Emma11'的记录 public void testSelect(){
//setUp();
String hql="from Tuser where name='Emma11'";
try{
List userList=session.createQuery(hql).list();
Tuser user=(Tuser)userList.get(0);
//Assert.assertEquals(user.getName(), "Emma11");
System.out.println("用户为:"+user.getId()+" "+user.getName());
}catch(HibernateException e){
e.printStackTrace();
//Assert.fail(e.getMessage());
}
teardown();
}
}
测试类:JunitTest.java package com.cn.hibernate.test;
import org.junit.Test; public class JunitTest { @Test
public void testInsert() {
} @Test
public void testselect() {
} }
该包对应的文件:
1.hibernate.cfg.xml(与sql server2008数据库进行连接的配置文件)
<?xml version="1.0"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!--显示执行的SQL语句-->
<property name="hibernate.show_sql">true</property>
<!--连接字符串-->
<property name="hibernate.connection.url">
jdbc:sqlserver://192.168.254.133:1433;DatabaseName=sample
</property>
<!--连接数据库的用户名-->
<property name="hibernate.connection.username">sa</property>
<!--数据库用户密码-->
<property name="hibernate.connection.password">123456</property>
<!--数据库连接池的大小-->
<property name="hibernate.connection.pool.size">20 </property>
<!--jdbc.fetch_size是指Hibernate每次从数据库中取出并放到JDBC的Statement中的记录条数。Fetch Size设的越大,读数据库的次数越少,速度越快,Fetch Size越小,读数据库的次数越多,速度越慢-->
<property name="jdbc.fetch_size">50</property>
<!--数据库驱动-->
<property name="hibernate.connection.driver_class">
com.microsoft.sqlserver.jdbc.SQLServerDriver
</property>
<!--选择使用的方言-->
<property name="dialect">
org.hibernate.dialect.SQLServerDialect
</property>
<!-- <property name="connection.pool_size">0</property> -->
<property name="c3p0.max_size">2000</property>
<property name="c3p0.min_size">200</property>
<property name="c3p0.timeout">5000</property>
<property name="c3p0.validate">false</property>
<!--
<property name="hibernate.transaction.factory_class">
net.sf.hibernate.transaction.JDBCTransactionFactory
</property>
-->
<!-- Enable Hibernate's automatic session context management -->
<!--<property name="current_session_context_class">thread</property>
--><property name="connection.autocommit">true</property>
<!--在启动时删除并重新创建数据库-->
<mapping resource="com/cn/beans/Tuser.hbm.xml"/>
</session-factory>
</hibernate-configuration>
结果:插入记录
查询记录: